Ludo recently fixed a problem with the exit status of "guix challenge". So now it (correctly) returns zero if the challenge is succesfull, and non-zero otherwise. It would be very useful however, if it would return a *different* non-zero if the challenge fails from when the challenge is inconclusive. For example, the current behaviour seems to be: Unsuccessful Challenge: ---------------------- guix challenge perl-algorithm-diff ; echo $? updating list of substitutes from 'http://mirror.hydra.gnu.org'... 100.0% updating list of substitutes from 'http://hydra.gnu.org'... 100.0% /gnu/store/ffs9llk3jrvq5qriwhx8swqz4pklzrwr-perl-algorithm-diff-1.1903 contents differ: local hash: 057h2zjp5ppziqq2g0c098rghkc9y2dsh2s2kvmywj06k29khhmc http://mirror.hydra.gnu.org/nar/ffs9llk3jrvq5qriwhx8swqz4pklzrwr-perl-algorithm-diff-1.1903: 0w6xvsnh9rn8h42xlc7v1m508g129b5zi2p6p2nizrxcyam9s4nk http://hydra.gnu.org/nar/ffs9llk3jrvq5qriwhx8swqz4pklzrwr-perl-algorithm-diff-1.1903: 0w6xvsnh9rn8h42xlc7v1m508g129b5zi2p6p2nizrxcyam9s4nk 1 Inconclusive Challenge: ---------------------- Guix> guix challenge pspp ; echo $? updating list of substitutes from 'http://mirror.hydra.gnu.org'... 100.0% updating list of substitutes from 'http://hydra.gnu.org'... 100.0% guix challenge: warning: no local build for '/gnu/store/0sdvdn9cjc1qikmgyh8qhi4r7lfnam18-pspp-0.10.1' guix challenge: error: no substitutes for '/gnu/store/0sdvdn9cjc1qikmgyh8qhi4r7lfnam18-pspp-0.10.1' 1 ... Guix> guix build pspp ... Succesfull Challenge: -------------------- Guix> guix challenge pspp ; echo $? updating list of substitutes from 'http://mirror.hydra.gnu.org'... 100.0% updating list of substitutes from 'http://hydra.gnu.org'... 100.0% 0 I suggest returning 2 in the inconclusive case. J' -- Avoid eavesdropping. Send strong encryted email. PGP Public key ID: 1024D/2DE827B3 fingerprint = 8797 A26D 0854 2EAB 0285 A290 8A67 719C 2DE8 27B3 See http://sks-keyservers.net or any PGP keyserver for public key.